This invention relates to liquid-crystal-on-silicon (LCoS) displays, and specifically, prevention of dark-banding in LCoS displays.
LCoS displays are used in consumer electronics, such as mobile devices, hand-held projectors and near-eye displays. LCoS displays include an LCoS panel that reflects source illumination incident thereon. The source illumination may be a repeating temporal sequence of color frames, each color frame corresponding to a different color, or optical spectrum. The LCoS panel includes a liquid-crystal layer that has ions therein that produce a residual DC voltage difference across the liquid-crystal layer. This residual DC voltage causes the LCoS display to produce images that include artifacts, specifically, one or more dark bands across the image. The image quality of such LCoS-based devices depends in part on reducing such dark-banding.